package week2;

import java.math.BigInteger;

public class Ex20 {
    public static void main(String[] args) {
        BigInteger ans = new BigInteger("1");
        int n = 100;
        for (int i = 1; i <= n; ++i)
            ans = ans.multiply(BigInteger.valueOf(i));
        String[] str = ans.toString().split("");
        int sum = 0;
        for (String s: str){
            sum += Integer.parseInt(s);
        }
        System.out.println(sum);
    }
}
